This invention relates to location means for the locking assemblies of the doors of freight containers, particularly standard dry cargo containers.
It is well established practice to lock the doors of I.S.O. containers by means of locking assemblies comprising elongate bars each mounted for controlled manual rotation about its longitudinal axis in a series of spaced location means welded to the outer surface of the door, the ends of a bar carrying cam members adapted to co-operate with associated abutment means secured to opposed members of the door frame to secure the door in said frame. Said door locking assemblies will hereinafter be referred to as `door locking assemblies of the type described`.
The location means for the bars of door locking assemblies of the type described each commonly comprise a substantially U-shaped bracket the free edges of which are welded to the surface of the door, said bracket having an insert piece located therein the surface of which, together with the internally rounded part of the bracket itself, provides a substantially cylindrical guide channel for a bar passing through the bracket. There are typically three such brackets per locking bar, one adjacent the bottom of the bar, one adjacent the top of the bar and one intermediate the length of the bar.
For protective, anti-corrosive puposes, it is necessary to treat the metal surface of the containers in question, for example by coating them with suitable paints. Such treatment to the doors of the containers is normally carried out after the above-detailed location brackets have been welded in position. Accordingly, the areas of the door behind the brackets cannot be treated in view of the presence of said brackets, and these areas are therefore particularly prone to corrosion.
If the doors were treated prior to attachment of the brackets and said brackets were then welded in position, it will be appreciated that substantial damage to the paintwork would occur. Further, the paint film adjacent the weld area would be almost all carbon in powder form, while there would be a scorched area radiating from the weld where the resin had been burned out of the film leaving it extremely porous. Both these features lead to moisture retention. Any attempt to repaint such areas would be doomed to failure.
It has been proposed to attempt to overcome this problem by first of all treating the door and then bolting the brackets to the door by extending the sidewalls of the brackets laterally and drilling holes in the brackets and the door panel. However, as well as being expensive, water can creep through the bolt holes to create corrosion and, effectively, this solution has merely displaced the area of the container open to attack.